mod = 1000000007
ans = 1
n = input()
n = int(n)
def qmod(a,n):
	res = 1
	while(n):
		if n % 2 == 1:
			res = res * n % mod
		a = a * a % mod
		n >>= 1
	return res % mod
for i in range(n):
	a = input()
	b = a.split(' ')
	ans = ans * (int(b[0]) + int(b[1])) % mod
	ans = ans*qmod(2,n) % mod
print(ans)